A 6-day-old, late-preterm male neonate presents to his pediatrician’s office with bilious emesis and is admitted for further evaluation. He was born at 36 weeks and 6 days via spontaneous vaginal delivery to a 23-year-old G4P4 mother with negative serologies, negative antenatal Group B Streptococcus testing, and no significant prenatal events. His stay in the newborn nursery was unremarkable. The neonate is exclusively breastfed, has no history of rectal bleeding, and passed meconium within the first 24 hours.
On admission, the patient was afebrile with a pulse of 115 beats/minute, respiratory rate of 32 breaths/minute, blood pressure of 67/31 mm Hg, and a pulse oximetry reading of 96% on room air. His weight was 2850 grams, down 13% from birth weight. He was alert, interactive, and in no apparent distress. His anterior fontanel was slightly sunken, and his mucous membranes were dry. His abdomen was soft and nondistended, without obvious palpable masses or hepatosplenomegaly, and there were active bowel sounds in all quadrants. The infant did not appear disturbed with attempts to examine his abdomen.
Initial laboratory studies, including a complete blood count, comprehensive metabolic profile, lactic acid, and inflammatory markers, were within normal limits.
An abdominal radiograph demonstrated nonobstructive bowel distension but was also notable for a 4-cm by 2.5-cm radiopaque structure within the right lower quadrant (Figure 1). Further imaging with an abdominal ultrasound revealed a 4-cm ovoid cystic structure in the right flank with a “double wall sign” consistent with a duplication cyst (Figure 2).
The neonate presenting with bilious emesis can occasionally present the clinician with a diagnostic challenge, as the differential diagnosis can be deceivingly narrow (Table). Classically, neonatal bilious emesis is presumed to be malrotation with volvulus until proven otherwise. However, several other conditions are capable of producing symptoms of bowel obstruction distal to the ampulla of Vater, including duodenal atresia, jejunoileal atresia, meconium ileus, necrotizing enterocolitis, and duplication cysts.
Often, the clinician chooses an abdominal radiograph for the initial evaluation of bilious emesis to evaluate for an obstructive bowel gas pattern, “double bubble” sign, or an underlying mass. If the abdominal film is unremarkable, further evaluation with an upper gastrointestinal (GI) series is the next step. In this patient, there was concern for a space-occupying mass in the right lower quadrant, prompting further investigation with an abdominal ultrasound instead of an upper GI series.
Surgery was consulted and took the patient to the operating room. An exam under anesthesia was notable for a palpable, well-circumscribed mobile mass in the right lower quadrant. The mass was found to be a duplication of the cecum sharing a common wall but not directly communicating with the true intestinal lumen. An ileocecectomy was executed with subsequent end-to-end ileocolotomy. There was no surgical evidence of intestinal malrotation or other obstructive lesions.
Enteric duplication cysts are congenital anomalies involving duplication at any point throughout the GI tract from the mouth to the rectum. They are most commonly found in the small intestine, although there have been cases describing lesions in the esophagus, colon, jejunum, and stomach.1 These lesions are highly variable in character, but they do not usually communicate directly with the true intestinal lumen. Rather, they are frequently found sharing a common smooth muscle wall and blood supply with the neighboring enteric tract.1-3
The incidence of enteric duplication cysts is estimated in the range of 1 in every 18,000 live births.1 Duplications may be suspected in the presence of a cystic mass in the fetal abdomen on prenatal ultrasound during the second or third trimesters. However, even with advancing technology, prenatal ultrasound only identifies approximately 20% to 30% of lesions.4,5
Clinically, the majority of symptomatic enteric duplications present in the infantile period. Approximately 70% of symptomatic enteric duplications will present within the first year of life, with up to 85% presenting by age 2 years.6-8 Their clinical presentation varies based on their size, location, and presence or absence of gastric mucosa. Accumulation of secretions can lead to fluid collection and subsequent mass effect, causing abdominal pain, distension, obstruction, or a lead point for intussusception.9,10 Moreover, the presence of gastric mucosa within the cyst, although rare, can cause ulceration and perforation of the neighboring mucosa leading to melena or hematochezia.10
The diagnosis is made via ultrasonography, either prenatally or postnatally. The lesions appear cystic in the majority of cases. The classic ultrasound finding consists of the “double wall” sign resulting from the relative hyperechogenicity of the mucosa-submucosa in relation to the hypoechoic muscularis propria.10 This sign is considered pathognomonic of duplication cysts.11,12
Treatment and management
Management of enteric duplication cysts is surgical. Many authors recommend complete primary excision of any symptomatic lesion close to the time of diagnosis to prevent repetitive or worsening symptoms. In asymptomatic cases, surgical resection is still the standard of care to prevent future complications and the risk of malignant transformation, although the optimal timing remains variable.8,10,13-14
Pathology confirmed this patient’s diagnosis in the immediate postoperative period. Over the next 3 days, the infant’s bowel function recovered, he was able to tolerate breastfeeding without emesis, was able to appropriately gain weight for his age, and was subsequently discharged.
Enteric duplication cysts are rare congenital malformations that occasionally may present with signs of bowel obstruction in the neonatal period. Clinicians should be mindful of these lesions when developing their differential diagnosis for the neonate presenting with bilious emesis.
1. Di Serafino M, Mercogliano C, Vallone G. Ultrasound evaluation of the enteric duplication cyst: the gut signature. J Ultrasound. 2015:19(2):131-133.
2. Lee NK, Kim S, Jean TY, et al. Complications of congenital and developmental abnormalities of the gastrointestinal tract in adolescents and adults: evaluation with multimodality imaging. Radiographics. 2010:30(6):1489-1507.
3. Park JY, Her KH. Kim BS, Maeng YH. A completely isolated intestinal duplication cyst mimicking ovarian cyst torsion in an adult. World J Gastroenterol. 2014:20(2):603-606.
4. .Basany L, Aepala R, Mohan Reddy Bellary M, Chitneni M. Intestinal obstruction due to ileal duplication cyst and malrotation in a preterm neonate. J Neonatal Surg. 2015:4(4):48.
5. Iijima S. A wandering abdominal mass in a neonate: an enteric duplication cyst mimicking an ovarian cyst. Case Rep Pediatr. 2017:2017:9209126.
6. Laje P, Flake AW, Adzick AS. Prenatal diagnosis and postnatal resection of intraabdominal enteric duplications. J Pediatr Surg. 2010:45(7):1554-1558.
7. Prada Arias M, Garcia Lorenzo F, Montero Sánchez M, Muquerza Vellibre R. Enteric duplication cyst resembling umbilical cord cyst. J Perinatol. 2006:26(6):368-370.
8. Foley PT, Sithasanan N, McEwing R, Lipsett J, Ford WD, Furness M. Enteric duplications presenting as antenatally detected abdominal cysts: is delayed resection appropriate? J Pediatr Surg. 2003:38(12):1810-1813.
9. Merrot T, Anastasescu R, Pankevych T, et al. Duodenal duplications. Clinical characteristics, embryological hypotheses, histological findings, treatment. Eur J Pediatr Surg. 2006:16(1):18-23.
10. Palacios A, De Vera M, Martinez-Escoriza JC. Prenatal sonographic findings of duodenal duplication: case report. J Clin Ultrasound. 2013:41(Suppl 1):1-5.
11. Munden MM, Hill JG. Ultrasound of the acute abdomen in children. Ultrasound Clin. 2010:5:113-135.
12. Cheng G, Soboleski D, Daneman A, Poenaru D, Hurlbut D. Sonographic pitfalls in the diagnosis of enteric duplication cysts. AJR Am J Roentgenol. 2005:184(2):521-525.
13. Khanna PC, Gawand V, Nawale AJ, Deshmukh T, Merchant SA. Complete large bowel duplication with paraduodenal cyst: prenatal sonographic features. Prenat Diagn. 2004:24(4):312-314.
14. Borgnon J, Durand C, Gourlaouen D, Sagot P, Sapin E. Antenatal detection of a communicating duodenal duplication. Eur J Pediatr Surg. 2003:13(2):130-133.